For the production of these high melting point high toughness metals, a hermetically closable and evacuable apparatus comprising a heatable reaction chamber and a coolable condensation chamber provided above the reaction chamber communicating each other with an intermediate connecting section is used, and magnesium and a chloride of said metals (titanium tetrachloride, for instance) are reacted in the reaction chamber, the formed magnesium chloride and unreacted magnesium are removed from the formed sponge metal by vacuum distillation, and the magnesium chloride and the magnesium are recovered in the cooled condensation chamber.
Such an apparatus is disclosed in Japanese Laying-Open Patent Publication No. 18717/72, for instance. In the apparatus of this kind, a problem arises concerning how to close the passage between the reaction chamber underneath and the condensation chamber above. In the apparatus disclosed in said patent publication, the passage of the intermediate connecting section is closed by a lid. But the mechanism of the lid is complicated and the lid is exposed to hot vapors of magnesium and magnesium chloride which pass within the proximity of said lid. Thus the lid is deformed by thermal strain and gradually fails to provide gas-tight closure.
A partially improved apparatus of this type is disclosed in Japanese Laying-Open Patent Publication No. 49922/77. In this apparatus, a lid of fusible metal such as magnesium, aluminum, zinc, or antimony is fixed by bolts so as to close the passage during the reduction reaction, and the lid is melted by a heating means at the stage of vacuum separation so as to open the connecting passage. The defect of the above-mentioned apparatus is eliminated by this improvement. But the apparatus is not quite satisfactory since a lid of a fusible metal, the surface of which is smoothly finished, has to be prepared for every run.
Both of the two above-cited apparatuses must be hoisted as a whole by a crane or the like for removal from the heating furnace and transfer to another position, since the two chambers cannot be separated at high temperature. This inconvenience will become even greater now that larger and larger apparatuses are being employed, since cranes with larger capacities and more spacious plant buildings will be required and construction cost will increase. This invention is intended to improve the efficiency of the above-mentioned apparatus overcoming the defects of prior art apparatuses by employing a seal pot structure as the means for closing the passage of the intermediate connecting section in an apparatus for reducing chlorides of high melting point high toughness metals comprising a reaction chamber and a condensation chamber connected by an intermediate connecting section.
We previously proposed an apparatus for producing high melting point high toughness metals by reduction of chloride thereof with an active metal which comprises a heatable reaction chamber in which the chloride and the active metal are reacted, an evacuable and coolable condensation chamber in which the active metal and the formed chloride which have been separated from the formed metal by evaporation in the reaction chamber are condensed, and an intermediate connecting section for communicating or cutting off the two chambers. The apparatus is characterized in that the intermediate connecting section is provided with a seal pot comprising a funnel body and a pan which receives the lower pipe of the funnel body and retains a fusible and vaporizable material and a heating means for melting and vaporizing the fusible and vaporizable material. (Japanese Laying-Open Patent Publication No. 126936/83 (Patent Application No. 8771/82))
However, this apparatus has a defect that the seal pot structure constitutes a high resistance to the flow of gases in comparison with the other parts when the apparatus is evacuated. The present invention has eliminated this defect.